<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>监听器应用-距离转换器</title>
    <script src="/js/vue.js"></script>
</head>
<body>
    <div id="app"></div>
</body>
<script>
    var vm = new Vue({
        el:'#app',
        data:{
            km: 0 ,
            m: 0
        },
        methods:{
            kmtom:function(val) {
                this.m = this.km * 1000;
            },
            mtom:function(val) {
                this.km = this.m / 1000;
            },
        },
        watch:{
            km : 'kmtom',
            m : 'mtom'
        }
    })
</script>
</html>